<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>async</title>
</head>
<body>
  
  <script>
    // 和 then 方法是一样的
    async function main() {
      // 1. 如果返回值是一个非 Promise类型的数据
      // return 123

      // 2. 如果返回的是一个 Promise 对象
      // return new Promise( (resolve, reject) => {
      //   // resolve('ok')
      //   reject('err')
      // })

      // 3. 抛出异常
      throw "Oh No"
    }

    let result = main();
    console.log(result);

    result.then( value => {
      console.log(value);
    }, reason => {
      console.log(reason);
    })


  </script>

</body>
</html>